A 3,5-dihydroxy-6-heptenoic acid derivative represented by (3R,5S) DOLE or (3R,5S) DOLM is known to be useful as an intermediate for a hyperlipemia preventive or curative medicine, or for a medicine for lowering cholesterol (HMG-CoA reductase inhibitor) (JP-A-1-279866, EP-A-304063, U.S. Pat. No. 5,011,930). Such a 3,5-dihydroxy-6-heptenoic acid derivative is produced as a racemic modification as it has an asymmetric carbon. It is known that an optically active isomer can be produced by optical resolution of the racemic modification by liquid chromatography employing an optical isomer separation HPLC column. (WO95/23125)